EAPSI: How Geomagnetic Field Strength Influences Magnetoreception and biodiversity within Magnetotactic Bacteria

Wagner Courtney L, Salt Lake City UT

Investigators

Abstract

Magnetotactic bacteria (MTB) are single celled, oxygen-sensitive organisms that synthesize iron-rich particles called magnetosomes. Magnetosomes are morphologically distinct and reflect the unique ecology of MTB. Therefore, when magnetosomes are preserved in the geological record they can be used as proxies for environmental change and microbial diversity, that in turn may be sensitive to climate. This project will test if magnetic field strength, which MTB use for orientation, modulates their phylogeny and magnetosome formation. Thus, this EAPSI will investigate how geomagnetic field strength affects biodiversity and biological function in modern environments, thereby improving the rigor of magnetosomes as proxies for oxygen-poor environments and microbial diversity in deep time. The researcher will collaborate with Dr. Yongxin Pan at the Chinese Academy of Sciences, Beijing, China. Dr. Pan is a global leader in MTB microbiology and access to his facilities and expertise will be indispensable for the success of this project. Magnetofossils (fossilized magnetosomes) have the potential to encode linkages between microbial diversity, ambient environmental conditions, and external environmental forces. The goal of this EAPSI project is to test if there is a measurable relationship between the strength of the geomagnetic field, phylogeny, and magnetosome biomineralization in MTB. The researcher will test if and how the external force of the geomagnetic field affects biodiversity in aquatic ecosystems. Furthermore, this project will demonstrate how the smallest and most sensitive organisms, microbes, respond to changes in geomagnetic field throughout time. The PI will work with Dr. Yongxin Pan, at the Chinese Academy of Sciences in Beijing, China, to culture field and laboratory samples of MTB in prescribed magnetic field intensities. She will then characterize these organisms using genomic analyses, transmission electron microscopy (TEM), and mineral magnetic measurements to determine how MTB cultured in variable magnetic field strengths differ phylogenetically and in magnetosome biomineralization (by observing morphology, crystallographic structure, composition, and magnetic grain size/domain state of magnetosomes). This award is through the East Asia and Pacific Summer Institutes program and supports summer research by a U.S. graduate student; it is jointly funded by the National Science Foundation and the Chinese Ministry of Science and Technology.